.690 ME/MV?

Anyone got any idea what kind of velocity,muzzle energy, and retained energy at 50 yds i might be getting with a .690 rd ball over 80 grs of 3f and 90 grs of 3f?

Both of those loads should provide a HUGE Thumpin WALLOP!! :rotf: AS FAR AS NUMBERS go I have no idea....but you know that somebody here will know!
Merry Christmas Rebel!!

Thanks, And Merry Christmas to you too Scalper and everyone else here.

I think you need this BC info to calc it yourself if it helps

Round Ball Ballistic Coefficient Table



Grain caliber dia. BC
Weight

47 32 0.315------ 0.0445179464155476
65 36 0.35------ 0.0498695718889059
80 38 0.375------- 0.0534670008354219
92 40 0.395------ 0.0554181479977785
127 45 0.44------ 0.0616533586031194
175 50 0.49------ 0.0685021591880576
235 54 0.535----- 0.0771646996782725
286 58 0.575 ----- 0.0812996574612334
325 62 0.6------- 0.0848475355054303
495 70 0.69------- 0.0977159344485979
550 72 0.715------- 0.101113461437348

Ok, thanks Bart, but i have No Idea what to do with all them numbers to get the answer. :grin:

Memorize them, then get back to us and we'll explain the difficult part. :rotf: :bull:

Yea, like with my memory thats likely to happen. :grin:

Sorry

The BC is a number which tells you how stream lined your bullet is. Or is not.

For every given caliber and bullet weigth with speed you enter the info into a calc which gives you the information you are looking for with drop over distance and (killing force my term) in foot pounds of energy. With distances from say 50 to any number of yards worked out.

So for any caliber pick the weight of the bullet, the speed, the diamater and the BC put in the calc and you get the info. Some of these calcs can also figure inches hold left or right in a side wind.

You can also try different zero settings in distance to see roughly how flat your bullet shoots. For example try putting in a zero distance of 100 yards print it and then try the calc with a 125 or 15o yard zero.

It might be that in shooting a 125 yard zero you are 2 inches high at 100 and 3 inches high at 50 yards is a good thing to know.
[url] http://www.eskimo.com/~jbm/calculations/calculations.html[/url]

Thanks Bart. The next time my granddaughter comes to visit i will see if she can help me figure all this out. :grin: Ohhh wait, that won't work. She graduated from High School last year and she doesn't know how to add, subtract, multiply, divide, spell, punctuate, etc. thanks to our wonderful School System and No Child Left Behind manure.

Count your blessings.
She could be learning how to multiply any time now.

Hey now, that ain't Even funny. Just for that you should tell me what kind of velocity and energy i should be getting with the .690's. :grin:

Math is not a problem my daughter figured math out as soon as she paid for her first gallon of gas. All of a sudden she became a expert on all sorts of things. Inflation, ecominics 1 plus one = 6.3.

No really that site has a number of usefull functions which are easy to work. All you need is the bullet speed and you enter the data.

If you can type on this forum you should be able to enter the info in the site. And with all the caliber data listed you can figure in a rough fashion for yourself how different calibers you might want to buy would work out in relation to what you already have.

Assuming these calcs are right it might be nice if the data was made available on the forum. In the past Every time I ask some people about BC's on RB people just shrug and look up at the sky. Expressive but not very help full.

Or if some one had some BC data on conical,s like maxi's and mini's or conventional hunters.

Bart, thanks again. But one of the problems i have is Not Knowing the bullet speed. That was why i wanted to know wht the Velocity would be with 80 and 90 grs of 3f. Ohh well, don't really matter i guess. I know whatever i hit with it is going to know it for sure. :grin:

The Lyman Black Powder Handbook says that shooting a .69 dia ball in a26 inch 12 guage modified choke barrel using 2Fg powder is:

80 grains = 881 FPS, 853.8 FT/LB
90 grains = 962 FPS, 1018.0 FT/LB
100 grains = 1043 FPS, 1196.7 FT/Lb

My roundball calculator says that at 50 yards the above muzzle velocities will be:

799 FPS, 702 FT/LB
866 FPS, 825.2 FT/LB
931 FPS, 953.8 FT/LB

IMO, the 3Fg will probably give a little higher velocity than the 2Fg given in the book but, for a ball park estimate which is about the best that can be made without a cronograph that will have to do for now. :grin:

The only information I have on a .69 caliber load comes from the back of the Dixie GW catalog, Page 667, which shows that a .69 Caliber rifle using a 412 Grain Round Ball in front of 110 grains of powder(It doesn't give the powder size) give 1500 fps. MV, and 2060 ME.( That ball weight seems wrong, as another table lists a .680 ball weighing 473.51 grains.)

There are also standard powder and ball charge loads for original guns, using a .680 RB, and FFg powder. the charges range from 70-80 grains of FFg. No listing for FFFg powder is given. NO velocity or energy levels are given but Dixie has a formula that you can use to determine velocity. Determine the ration between the weight of the powder charge and the weight of the ball being used. Then refer to the table.

I used your 80 grain, and 90 grain charges and a arbitrary 470 Grain RB. The ratio of weight from powder to ball is 5.875 for 80 grains, and 5.222 grains for the 90 grain load. The chart lists 5:1 at 1535; 5 1/2: to 1 at 1480, and 6:1 at 1425.

The 80 grain charge is closer to the 6:1 formula, so I would think you are getting something around 1400 fps. The 90 grain charge is right between the 5:1 and 5 1/2 : 1 formulas, so take your pick, or split the difference( 1510 fps).

You do know that the pressures and expected velocities for FFFg powder will be higher than FFg powder? I think if you do penetration testing, there will be no good reason to be using that 90 grain load. Using the lighter loads will save your gun, and your shoulder. A 70 grain charge should still push that huge ball out at around 1400 fps, and that is more than enough to kill deer out to 100 yards.

My Hodgdon Reloading Manual does not go higher than .58 caliber with its data.

I can only hope that someone with a similar rifle owns his own chronograph and will answer your questions more directly. You can buy a Chrony Chronograph through Sportsman's Guide for about $80.00 plus shipping. Its worth the investment. You may even be able to help someone else out here on the forum with a question about velocity, for a given load. :hmm: :thumbsup:

My roundball program says the weight of a .690 diameter lead ball is 492.8 grains.
The Lyman Black Powder Handbook which gave the velocities I mentioned above said the weight of the .690 diameter test balls was 494 grains.

Although the Dixie Catalog is a handy reference I think the Lyman test data might be a little closer to the results that could be expected.

Oh, by the way, the .690 diameter balls in the Lyman tests were patched with .020 thick Ox-Yoke pre lubed patches.

Thanks to you both Zonie and Paul. The rd ball is supposed to weigh around 492 gr. I think it will do a number on deer or elk out to 50-70 yds. I am getting decent groups with it but am still experimenting to see if i can improve them. This is out of a 27" barreled New Englander.

Rebel trust me my friend that load will be a real thumper at 50 yards. My .715 ball on top of 82gr 2F flipped that buck I got at 30 yards, (was slight quartering to me with his right shoulder facing me). When the smoke cleared he was laying on his left side with his arse to me. That big ball is like a freight train. :thumbsup:

Thanks, i kinda figured that i for sure would not want to get hit by the load i use. Hope to get it shooting even better groups by next year and maybe get to go use it on an elk.